Formation of Bifluorenylidene from 9-Mercaptofluorene via a Sulfide Autoxidation-Anionic Autoxidation-Elimination Sequence.

Abstract Bifluorenylidene 1 was formed quantitatively when 9-mercaptofluorene 3 was treated with base and exposed to air. The initial step was established to be an intermolecular autoxidation of sulphide ion to form the disulphide 6 . An intramolecular autoxidation of the dianion 8 derived from 6 was expected to afford a 1,2-dithietane derivative 9 which eliminated sulphur to give bifluorenylidene 1 .